Boiler tubes or water-wall tubes are used to carry high pressure steam. These tubes or pipes are generally disposed about the periphery of a firebox where the high pressure steam is generated and used to drive steam turbines which in turn drive electric generators. Such tubes or pipes must be periodically repaired and replaced because they operate under high pressure and corrosive conditions which cause serious wear and even destruction of the tubes or pipes. The discussion herein uses the term tube, but it should be understood that the invention applies to tools used to finish tubes, pipes or any other types of conduits. The damaged portions of the tubes are cut out and an end finishing tool is used to finish the ends of the tubes for subsequent welding or other joining techniques for installation of new tubes or parts thereof. The end finishing tool must be securely fastened to the end of the tube to be finished. This is typically done by using on the distal end of the tool a clamp which fits into the tube and has a number of ribs which can be driven radially outwardly to grip the inner surface of the tube. Then the machining or finishing of the end of the tube is done and the clamp is backed off and the tool extracted. Clamping is improved by using a more gentle taper as opposed to a sharper taper on the camming surface which drives the ribs: the gentler the taper incline the more contact surface there is available to drive the ribs radially outwardly. However, the greater contact area makes it more difficult to release the ribs when the tool is to be extracted. One technique used by the laborer to release the ribs is to wiggle the tool but this is not very successful, especially with the good grip obtained with the gentle taper. Often the laborer is forced to take a hammer to the actuator rod which can damage or wholly incapacitate the tool so that manual machining must be done until the tool can be replaced or repaired.